When you have finished the contents of your tetra-pak, fill it with soapy water and give it shake, then rinse it out.

2.

Top-and-tail your tetra-pak using sharp scissors (be careful!) Now you can see inside check it's clean, and if not, give it a wipe and a dry with a tea towel.

3.

Flatten your tetra-pak, on a hard surface, creasing the long sides.

4.

Un-flatten your tetra-pak and push the two long sides inwards, then flatten it again.

5.

Now fold the bottom three inches of your tetra-pak upwards, and crease it firmly on a hard surface.

6.

The remaining top part of your tetra-pak will form the front flap of the wallet. On this section cut away the front, and the sides of the tetra, leaving a single piece of card.

7.

Your tetra-pak should now roughly resemble a wallet! Next staple the inner pieces of card from the two compartments together.

8.

The front flap can be cut into any shape you wish. It can have rounded corners or zig-zag edges - whatever you feel like having! So trim appropriately and then cut a small hole in the centre of the flap.

9.

Fold the front flap down over the wallet and again crease well.

10.

Get your elastic band, poke one end through thehole so that you can see a small loop. Then thread the other end of the elastic band through the loop and pull tight. You should now have a larger loop of elastic band which is secured onto the front flap. this can be stretched over the body of the wallet to hold it shut.

"Bicycology uses creative methods to encourage environmental responsibility.
Its aim is to promoting cycling as a healthy, practical and enjoyablealternative to high-carbon lifestyles, and to challenge the politics and economics that have led us down the road to environmental destruction and massive global injustice"